XML/XPath
You are encouraged to solve this task according to the task description, using any language you may know.
Perform the following three XPath queries on the XML Document below:
- Retrieve the first "item" element
- Perform an action on each "price" element (print it out)
- Get an array of all the "name" elements
XML Document:
<inventory title="OmniCorp Store #45x10^3"><item upc="123456789" stock="12"> <name>Invisibility Cream</name> <price>14.50</price> <description>Makes you invisible</description> </item> <item upc="445322344" stock="18"> <name>Levitation Salve</name> <price>23.99</price> <description>Levitate yourself for up to 3 hours per application</description> </item> <item upc="485672034" stock="653"> <name>Blork and Freen Instameal</name> <price>4.95</price> <description>A tasty meal in a tablet; just add water</description> </item> <item upc="132957764" stock="44"> <name>Grob winglets</name> <price>3.56</price> <description>Tender winglets of Grob. Just add water</description> </item> </inventory>
AutoHotkey
With regular expressions <lang AutoHotkey>FileRead, inventory, xmlfile.xml
RegExMatch(inventory, "<item.*?</item>", item1) MsgBox % item1
pos = 1 While, pos := RegExMatch(inventory, "<price>(.*?)</price>", price, pos + 1)
MsgBox % price1
While, pos := RegExMatch(inventory, "<name>.*?</name>", name, pos + 1)
names .= name . "`n"
MsgBox % names</lang>
<lang AutoHotkey>#Include xpath.ahk
xpath_load(doc, "xmlfile.xml")
- Retrieve the first "item" element
MsgBox % xpath(doc, "/inventory/section[1]/item[1]/text()")
- Perform an action on each "price" element (print it out)
prices := xpath(doc, "/inventory/section/item/price/text()") Loop, Parse, prices,`,
reordered .= A_LoopField "`n"
MsgBox % reordered
- Get an array of all the "name" elements
MsgBox % xpath(doc, "/inventory/section/item/name")</lang>
AppleScript
Using System Events
AppleScript has no-built in support for XPath, but it could be used via a 'do shell script' command. Here's a solution using Apple System Events.
<lang AppleScript>set theXMLdata to "<inventory title=\"OmniCorp Store #45x10^3\">
<item upc=\"123456789\" stock=\"12\"> <name>Invisibility Cream</name> <price>14.50</price> <description>Makes you invisible</description> </item> <item upc=\"445322344\" stock=\"18\"> <name>Levitation Salve</name> <price>23.99</price> <description>Levitate yourself for up to 3 hours per application</description> </item> <item upc=\"485672034\" stock=\"653\"> <name>Blork and Freen Instameal</name> <price>4.95</price> <description>A tasty meal in a tablet; just add water</description> </item> <item upc=\"132957764\" stock=\"44\"> <name>Grob winglets</name> <price>3.56</price> <description>Tender winglets of Grob. Just add water</description> </item>
</inventory>"
on getElementValuesByName(theXML, theNameToFind) set R to {} tell application "System Events" repeat with i in theXML set {theName, theElements} to {i's name, i's XML elements} if (count of theElements) > 0 then set R to R & my getElementValuesByName(theElements, theNameToFind) if theName = theNameToFind then set R to R & i's value end repeat end tell return R end getElementValuesByName
on getBlock(theXML, theItem, theInstance) set text item delimiters to "" repeat with i from 1 to theInstance set {R, blockStart, blockEnd} to {{}, "<" & theItem & space, "</" & theItem & ">"} set x to offset of blockStart in theXML if x = 0 then exit repeat set y to offset of blockEnd in (characters x thru -1 of theXML as string) if y = 0 then exit repeat set R to characters x thru (x + y + (length of blockEnd) - 2) of theXML as string set theXML to characters (y + (length of blockEnd)) thru -1 of theXML as string end repeat return R end getBlock
tell application "System Events" set xmlData to make new XML data with properties {name:"xmldata", text:theXMLdata}
return my getBlock(xmlData's text, "item", 1) -- Solution to part 1 of problem. return my getElementValuesByName(xmlData's contents, "name") -- Solution to part 2 of problem. return my getElementValuesByName(xmlData's contents, "price") -- Solution to part 3 of problem.
end tell</lang>Output for the three results (respectively):<lang AppleScript>"<item upc=\"123456789\" stock=\"12\">
<name>Invisibility Cream</name>
<price>14.50</price>
<description>Makes you invisible</description>
</item>"
{"Invisibility Cream", "Levitation Salve", "Blork and Freen Instameal", "Grob winglets"}
{"14.50", "23.99", "4.95", "3.56"}</lang>
C#
<lang csharp>XmlReader XReader;
// Either read the xml from a string ... XReader = XmlReader.Create(new StringReader("<inventory title=... </inventory>"));
// ... or read it from the file system. XReader = XmlReader.Create("xmlfile.xml");
// Create a XPathDocument object (which implements the IXPathNavigable interface) // which is optimized for XPath operation. (very fast). IXPathNavigable XDocument = new XPathDocument(XReader);
// Create a Navigator to navigate through the document. XPathNavigator Nav = XDocument.CreateNavigator(); Nav = Nav.SelectSingleNode("//item");
// Move to the first element of the selection. (if available). if(Nav.MoveToFirst()) {
Console.WriteLine(Nav.OuterXml); // The outer xml of the first item element.
}
// Get an iterator to loop over multiple selected nodes. XPathNodeIterator Iterator = XDocument.CreateNavigator().Select("//price");
while (Iterator.MoveNext()) {
Console.WriteLine(Iterator.Current.Value);
}
Iterator = XDocument.CreateNavigator().Select("//name");
// Use a generic list. List<string> NodesValues = new List<string>();
while (Iterator.MoveNext()) {
NodesValues.Add(Iterator.Current.Value);
}
// Convert the generic list to an array and output the count of items. Console.WriteLine(NodesValues.ToArray().Length);</lang>
C++
<lang cpp>#include <vector>
- include <string>
- include <iostream>
- include <boost/regex.hpp>
- include <algorithm>
- include <iterator>
int main( ) {
const std::string xmltext(
"<inventory title=\"OmniCorp Store #45x10^3\">"
"
" "
"
"</inventory>" ) ;
std::string::size_type found = xmltext.find( "<item" , 0 ) ; //beginning of first item
std::string::size_type foundnext = xmltext.find( "</item>" , found + 5 ) ; //and its end
std::cout << "The first item is\n" << xmltext.substr( found + 5 , foundnext - ( found + 5 ) ) << '\n' ;
std::string::const_iterator start , end ;
start = xmltext.begin( ) ;
end = xmltext.end( ) ;
boost::match_results<std::string::const_iterator> what ;
boost::regex pricefind( "<price>(\\d+\\.?\\d+)</price>" ) ;//this regex finds the prices
start = xmltext.begin( ) ;
std::cout << "The prices are:\n" ;
while ( boost::regex_search( start , end , what , pricefind ) ) {
std::string price( what[ 1 ].first , what[ 1 ].second ) ;//find the first price
std::cout << price << std::endl ;
start = what[ 1 ].second ; //continue search after first price found
}
start = xmltext.begin( ) ;
std::vector<std::string> names ;
boost::regex namefind( "<name>(.+?)</name>" ) ; //find characters, be greedy!
while ( boost::regex_search ( start , end , what , namefind ) ) {
std::string name ( what[ 1 ].first , what[ 1 ].second ) ;
names.push_back( name ) ;
start = what[ 1 ].second ;
}
std::cout << "The following name elements were found in the xml string:\n" ;
std::copy( names.begin( ) , names.end( ) , std::ostream_iterator<std::string>( std::cout , "\n" )) ;
return 0 ;
}</lang>
Caché ObjectScript
<lang cos>Class XML.Inventory [ Abstract ] {
XData XMLData { <inventory title="OmniCorp Store #45x10^3">
<item upc="123456789" stock="12"> <name>Invisibility Cream</name> <price>14.50</price> <description>Makes you invisible</description> </item> <item upc="445322344" stock="18"> <name>Levitation Salve</name> <price>23.99</price> <description>Levitate yourself for up to 3 hours per application</description> </item> <item upc="485672034" stock="653"> <name>Blork and Freen Instameal</name> <price>4.95</price> <description>A tasty meal in a tablet; just add water</description> </item> <item upc="132957764" stock="44"> <name>Grob winglets</name> <price>3.56</price> <description>Tender winglets of Grob. Just add water</description> </item>
</inventory> }
ClassMethod QueryXMLDoc(Output names As %List) As %Status {
// get xml stream from the 'XData' block contained in this class
Set xdata=##class(%Dictionary.CompiledXData).%OpenId($this_"||XMLData",, .sc)
If $$$ISERR(sc) Quit sc
Set sc=##class(%XML.XPATH.Document).CreateFromStream(xdata.Data, .xdoc)
If $$$ISERR(sc) Quit sc
// retrieve the first 'item' element
Set sc=xdoc.EvaluateExpression("//section[1]", "item[1]", .res)
// perform an action on each 'price' element (print it out)
Set sc=xdoc.EvaluateExpression("//price", "text()", .res)
If $$$ISERR(sc) Quit sc
For i=1:1:res.Count() {
If i>1 Write ", " Write res.GetAt(i).Value
}
// get an array of all the 'name' elements
Set sc=xdoc.EvaluateExpression("//item", "name", .res)
If $$$ISERR(sc) Quit sc
Set key=""
Do {
Set dom=res.GetNext(.key) If '$IsObject(dom) Quit While dom.Read() { If dom.HasValue Set $List(names, key)=dom.Value }
} While key'="" // finished Quit $$$OK
}
}</lang>
- Examples:
USER>Do ##class(XML.Inventory).QueryXMLDoc(.list) 14.50, 23.99, 4.95, 3.56 USER>Write $ListToString(list, ", ") Invisibility Cream, Levitation Salve, Blork and Freen Instameal, Grob winglets
CoffeeScript
<lang coffeescript> doc = new DOMParser().parseFromString '
<inventory title="OmniCorp Store #45x10^3">
<item upc="123456789" stock="12">
<name>Invisibility Cream</name>
<price>14.50</price>
<description>Makes you invisible</description>
</item>
<item upc="445322344" stock="18">
<name>Levitation Salve</name>
<price>23.99</price>
<description>Levitate yourself for up to 3 hours per application</description>
</item>
<item upc="485672034" stock="653">
<name>Blork and Freen Instameal</name>
<price>4.95</price>
<description>A tasty meal in a tablet; just add water</description>
</item>
<item upc="132957764" stock="44">
<name>Grob winglets</name>
<price>3.56</price>
<description>Tender winglets of Grob. Just add water</description>
</item>
</inventory>
', 'text/xml' </lang>
# "doc" is the XML as a Document object. Click expand to see parsing code ⇒
<lang coffeescript>
- Retrieve the first "item" element
doc.evaluate('//item', doc, {}, 7, {}).snapshotItem 0
- Perform an action on each "price" element (print it out)
prices = doc.evaluate "//price", doc, {}, 7, {} for i in [0...prices.snapshotLength] by 1
console.log prices.snapshotItem(i).textContent
- Get an array of all the "name" elements
names = doc.evaluate "//name", doc, {}, 7, {} names = for i in [0...names.snapshotLength] by 1
names.snapshotItem i
</lang>
ColdFusion
<lang cfm><cfsavecontent variable="xmlString"> <inventory ... </inventory> </cfsavecontent> <cfset xml = xmlParse(xmlString)> <cfset itemSearch = xmlSearch(xml, "//item")> <cfset item = itemSearch[1]> <cfset priceSearch = xmlSearch(xml, "//price")> <cfloop from="1" to="#arrayLen(priceSearch)#" index="i">
#priceSearch[i].xmlText#
</cfloop> <cfset names = xmlSearch(xml, "//name")> <cfdump var="#variables#"></lang>
Common Lisp
<lang lisp>(dolist (system '(:xpath :cxml-stp :cxml))
(asdf:oos 'asdf:load-op system))
(defparameter *doc* (cxml:parse-file "xml" (stp:make-builder)))
(xpath:first-node (xpath:evaluate "/inventory/section[1]/item[1]" *doc*))
(xpath:do-node-set (node (xpath:evaluate "/inventory/section/item/price/text()" *doc*))
(format t "~A~%" (stp:data node)))
(defun node-array (node-set)
(coerce (xpath:all-nodes node-set) 'vector))
(node-array
(xpath:evaluate "/inventory/section/item/name" *doc*))</lang>
D
It is important to note that the KXML library currently only supports XPath minimally.
<lang d>import kxml.xml; char[]xmlinput = "<inventory title=\"OmniCorp Store #45x10^3\">
<item upc=\"123456789\" stock=\"12\"> <name>Invisibility Cream</name> <price>14.50</price> <description>Makes you invisible</description> </item> <item upc=\"445322344\" stock=\"18\"> <name>Levitation Salve</name> <price>23.99</price> <description>Levitate yourself for up to 3 hours per application</description> </item> <item upc=\"485672034\" stock=\"653\"> <name>Blork and Freen Instameal</name> <price>4.95</price> <description>A tasty meal in a tablet; just add water</description> </item> <item upc=\"132957764\" stock=\"44\"> <name>Grob winglets</name> <price>3.56</price> <description>Tender winglets of Grob. Just add water</description> </item>
</inventory> "; void main() {
auto root = readDocument(xmlinput);
auto firstitem = root.parseXPath("inventory/section/item")[0];
foreach(price;root.parseXPath("inventory/section/item/price")) {
std.stdio.writefln("%s",price.getCData);
}
auto namearray = root.parseXPath("inventory/section/item/name");
}</lang>
Delphi
<lang Delphi>program XMLXPath;
{$APPTYPE CONSOLE}
uses ActiveX, MSXML;
const
XML = '<inventory title="OmniCorp Store #45x10^3">' + '' + ' <item upc="123456789" stock="12">' + ' <name>Invisibility Cream</name>' + ' <price>14.50</price>' + ' <description>Makes you invisible</description>' + ' </item>' + ' <item upc="445322344" stock="18">' + ' <name>Levitation Salve</name>' + ' <price>23.99</price>' + ' <description>Levitate yourself for up to 3 hours per application</description>' + ' </item>' + ' ' + '' + ' <item upc="485672034" stock="653">' + ' <name>Blork and Freen Instameal</name>' + ' <price>4.95</price>' + ' <description>A tasty meal in a tablet; just add water</description>' + ' </item>' + ' <item upc="132957764" stock="44">' + ' <name>Grob winglets</name>' + ' <price>3.56</price>' + ' <description>Tender winglets of Grob. Just add water</description>' + ' </item>' + ' ' + '</inventory>';
var
i: Integer; s: string; lXMLDoc: IXMLDOMDocument2; lNodeList: IXMLDOMNodeList; lNode: IXMLDOMNode; lItemNames: array of string;
begin
CoInitialize(nil);
lXMLDoc := CoDOMDocument.Create;
lXMLDoc.setProperty('SelectionLanguage', 'XPath');
lXMLDoc.loadXML(XML);
Writeln('First item node:');
lNode := lXMLDoc.selectNodes('//item')[0];
Writeln(lNode.xml);
Writeln();
lNodeList := lXMLDoc.selectNodes('//price');
for i := 0 to lNodeList.length - 1 do
Writeln('Price = ' + lNodeList[i].text);
Writeln();
lNodeList := lXMLDoc.selectNodes('//item/name');
SetLength(lItemNames, lNodeList.length);
for i := 0 to lNodeList.length - 1 do
lItemNames[i] := lNodeList[i].text;
for s in lItemNames do
Writeln('Item name = ' + s);
end.</lang>
Output: <lang>First item node: <item upc="123456789" stock="12"> <name>Invisibility Cream</name> <price>14.50</price> <description>Makes you invisible</description> </item>
Price = 14.50 Price = 23.99 Price = 4.95 Price = 3.56
Item name = Invisibility Cream Item name = Levitation Salve Item name = Blork and Freen Instameal Item name = Grob winglets</lang>
E
(currently a very early work in progress/draft library; design comments welcome)
<lang e>? def xml__quasiParser := <import:org.switchb.e.xml.makeXMLQuasiParser>() > def xpath__quasiParser := xml__quasiParser.xPathQuasiParser() > null
? def doc := xml`<inventory title="OmniCorp Store #45x10^3"> >
>
> </inventory>`
- value: xml`...`
? doc[xpath`inventory/section/item`][0]
- value: xml`<item stock="12" upc="123456789">
- <name>Invisibility Cream</name>
- <price>14.50</price>
- <description>Makes you invisible</description>
- </item>`
? for price in doc[xpath`inventory/section/item/price/text()`] { println(price :String) } 14.50 23.99 4.95 3.56
? doc[xpath`inventory/section/item/name`]
- value: [xml`<name>Invisibility Cream</name>`,
- xml`<name>Levitation Salve</name>`,
- xml`<name>Blork and Freen Instameal</name>`,
- xml`<name>Grob winglets</name>`]
</lang>
Erlang
<lang erlang> -module(xml_xpath). -include_lib("xmerl/include/xmerl.hrl").
-export([main/0]).
main() ->
XMLDocument =
"<inventory title=\"OmniCorp Store #45x10^3\">
<item upc=\"123456789\" stock=\"12\">
<name>Invisibility Cream</name>
<price>14.50</price>
<description>Makes you invisible</description>
</item>
<item upc=\"445322344\" stock=\"18\">
<name>Levitation Salve</name>
<price>23.99</price>
<description>Levitate yourself for up to 3 hours per application</description>
</item>
<item upc=\"485672034\" stock=\"653\">
<name>Blork and Freen Instameal</name>
<price>4.95</price>
<description>A tasty meal in a tablet; just add water</description>
</item>
<item upc=\"132957764\" stock=\"44\">
<name>Grob winglets</name>
<price>3.56</price>
<description>Tender winglets of Grob. Just add water</description>
</item>
</inventory>",
{Document,_} = xmerl_scan:string(XMLDocument),
io:format("First item:\n~s\n",
[lists:flatten(
xmerl:export_simple(
[hd(xmerl_xpath:string("//item[1]", Document))],
xmerl_xml, [{prolog, ""}]))]),
io:format("Prices:\n"),
[ io:format("~s\n",[Content#xmlText.value])
|| #xmlElement{content = [Content|_]} <- xmerl_xpath:string("//price", Document)],
io:format("Names:\n"),
[ Content#xmlText.value
|| #xmlElement{content = [Content|_]} <- xmerl_xpath:string("//name", Document)].
</lang>
Output:
First item:
<item upc="123456789" stock="12">
<name>Invisibility Cream</name>
<price>14.50</price>
<description>Makes you invisible</description>
</item>
Prices:
14.50
23.99
4.95
3.56
Names:
["Invisibility Cream","Levitation Salve",
"Blork and Freen Instameal","Grob winglets"]
F#
<lang fsharp> open System.IO open System.Xml.XPath
let xml = new StringReader(""" <inventory title="OmniCorp Store #45x10^3">
<item upc="123456789" stock="12"> <name>Invisibility Cream</name> <price>14.50</price> <description>Makes you invisible</description> </item> <item upc="445322344" stock="18"> <name>Levitation Salve</name> <price>23.99</price> <description>Levitate yourself for up to 3 hours per application</description> </item> <item upc="485672034" stock="653"> <name>Blork and Freen Instameal</name> <price>4.95</price> <description>A tasty meal in a tablet; just add water</description> </item> <item upc="132957764" stock="44"> <name>Grob winglets</name> <price>3.56</price> <description>Tender winglets of Grob. Just add water</description> </item>
</inventory> """)
let nav = XPathDocument(xml).CreateNavigator()
// first "item"; throws if none exists let item = nav.SelectSingleNode(@"//item[1]")
// apply a operation (print text value) to all price elements for price in nav.Select(@"//price") do
printfn "%s" (price.ToString())
// array of all name elements let names = seq { for name in nav.Select(@"//name") do yield name } |> Seq.toArray</lang>
Factor
<lang factor>
! Get first item element """<inventory title="OmniCorp Store #45x10^3">
<item upc="123456789" stock="12"> <name>Invisibility Cream</name> <price>14.50</price> <description>Makes you invisible</description> </item> <item upc="445322344" stock="18"> <name>Levitation Salve</name> <price>23.99</price> <description>Levitate yourself for up to 3 hours per application</description> </item> <item upc="485672034" stock="653"> <name>Blork and Freen Instameal</name> <price>4.95</price> <description>A tasty meal in a tablet; just add water</description> </item> <item upc="132957764" stock="44"> <name>Grob winglets</name> <price>3.56</price> <description>Tender winglets of Grob. Just add water</description> </item>
</inventory>""" string>xml "item" deep-tag-named
! Print out prices """<inventory title="OmniCorp Store #45x10^3">
<item upc="123456789" stock="12"> <name>Invisibility Cream</name> <price>14.50</price> <description>Makes you invisible</description> </item> <item upc="445322344" stock="18"> <name>Levitation Salve</name> <price>23.99</price> <description>Levitate yourself for up to 3 hours per application</description> </item> <item upc="485672034" stock="653"> <name>Blork and Freen Instameal</name> <price>4.95</price> <description>A tasty meal in a tablet; just add water</description> </item> <item upc="132957764" stock="44"> <name>Grob winglets</name> <price>3.56</price> <description>Tender winglets of Grob. Just add water</description> </item>
</inventory>""" string>xml "price" deep-tags-named [ children>> first ] map
! Array of all name elements """<inventory title="OmniCorp Store #45x10^3">
<item upc="123456789" stock="12"> <name>Invisibility Cream</name> <price>14.50</price> <description>Makes you invisible</description> </item> <item upc="445322344" stock="18"> <name>Levitation Salve</name> <price>23.99</price> <description>Levitate yourself for up to 3 hours per application</description> </item> <item upc="485672034" stock="653"> <name>Blork and Freen Instameal</name> <price>4.95</price> <description>A tasty meal in a tablet; just add water</description> </item> <item upc="132957764" stock="44"> <name>Grob winglets</name> <price>3.56</price> <description>Tender winglets of Grob. Just add water</description> </item>
</inventory>""" string>xml "name" deep-tags-named </lang>
Go
Using the standard encoding/xml package:
<lang go>package main
import ( "encoding/xml" "fmt" "log" "os" )
type Inventory struct { XMLName xml.Name `xml:"inventory"` Title string `xml:"title,attr"` Sections []struct { XMLName xml.Name `xml:"section"` Name string `xml:"name,attr"` Items []struct { XMLName xml.Name `xml:"item"` Name string `xml:"name"` UPC string `xml:"upc,attr"` Stock int `xml:"stock,attr"` Price float64 `xml:"price"` Description string `xml:"description"` } `xml:"item"` } `xml:"section"` }
// To simplify main's error handling func printXML(s string, v interface{}) { fmt.Println(s) b, err := xml.MarshalIndent(v, "", "\t") if err != nil { log.Fatal(err) } fmt.Println(string(b)) fmt.Println() }
func main() { fmt.Println("Reading XML from standard input...")
var inv Inventory dec := xml.NewDecoder(os.Stdin) if err := dec.Decode(&inv); err != nil { log.Fatal(err) }
// At this point, inv is Go struct with all the fields filled // in from the XML data. Well-formed XML input that doesn't // match the specification of the fields in the Go struct are // discarded without error.
// We can reformat the parts we parsed: //printXML("Got:", inv)
// 1. Retrieve first item: item := inv.Sections[0].Items[0] fmt.Println("item variable:", item) printXML("As XML:", item)
// 2. Action on each price: fmt.Println("Prices:") var totalValue float64 for _, s := range inv.Sections { for _, i := range s.Items { fmt.Println(i.Price) totalValue += i.Price * float64(i.Stock) } } fmt.Println("Total inventory value:", totalValue) fmt.Println()
// 3. Slice of all the names: var names []string for _, s := range inv.Sections { for _, i := range s.Items { names = append(names, i.Name) } } fmt.Printf("names: %q\n", names) }</lang>
- Output:
Reading XML from standard input...
item variable: {{ item} Invisibility Cream 123456789 12 14.5 Makes you invisible}
As XML:
<item upc="123456789" stock="12">
<name>Invisibility Cream</name>
<price>14.5</price>
<description>Makes you invisible</description>
</item>
Prices:
14.5
23.99
4.95
3.56
Total inventory value: 3994.81
names: ["Invisibility Cream" "Levitation Salve" "Blork and Freen Instameal" "Grob winglets"]
<lang go>package main
import (
"fmt" "os"
"launchpad.net/xmlpath"
)
func main() {
f, err := os.Open("test3.xml")
if err != nil {
fmt.Println(err)
return
}
n, err := xmlpath.Parse(f)
f.Close()
if err != nil {
fmt.Println(err)
return
}
q1 := xmlpath.MustCompile("//item")
if _, ok := q1.String(n); !ok {
fmt.Println("no item")
}
q2 := xmlpath.MustCompile("//price")
for it := q2.Iter(n); it.Next(); {
fmt.Println(it.Node())
}
q3 := xmlpath.MustCompile("//name")
names := []*xmlpath.Node{}
for it := q3.Iter(n); it.Next(); {
names = append(names, it.Node())
}
if len(names) == 0 {
fmt.Println("no names")
}
}</lang>
- Output:
14.50 23.99 4.95 3.56
Groovy
<lang groovy>def inventory = new XmlSlurper().parseText("<inventory...") //optionally parseText(new File("inv.xml").text) def firstItem = inventory.section.item[0] //1. first item inventory.section.item.price.each { println it } //2. print each price def allNamesArray = inventory.section.item.name.collect {it} //3. collect item names into an array</lang>
Haskell
<lang haskell>import Data.List import Control.Arrow import Control.Monad
takeWhileIncl :: (a -> Bool) -> [a] -> [a] takeWhileIncl _ [] = [] takeWhileIncl p (x:xs)
| p x = x : takeWhileIncl p xs
| otherwise = [x]
getmultiLineItem n = takeWhileIncl(not.isInfixOf ("</" ++ n)). dropWhile(not.isInfixOf ('<': n)) getsingleLineItems n = map (takeWhile(/='<'). drop 1. dropWhile(/='>')). filter (isInfixOf ('<': n))
main = do
xml <- readFile "./Rosetta/xmlpath.xml"
let xmlText = lines xml
putStrLn "\n== First item ==\n"
mapM_ putStrLn $ head $ unfoldr (Just. liftM2 (id &&&) (\\) (getmultiLineItem "item")) xmlText
putStrLn "\n== Prices ==\n"
mapM_ putStrLn $ getsingleLineItems "price" xmlText
putStrLn "\n== Names ==\n"
print $ getsingleLineItems "name" xmlText</lang>
Using the Haskell XML Toolkit (HXT): <lang haskell>{-# LANGUAGE Arrows #-} import Text.XML.HXT.Arrow {- For HXT version >= 9.0, use instead: import Text.XML.HXT.Core -}
deepElem name = deep (isElem >>> hasName name)
process = proc doc -> do
item <- single (deepElem "item") -< doc _ <- listA (arrIO print <<< deepElem "price") -< doc names <- listA (deepElem "name") -< doc returnA -< (item, names)
main = do
[(item, names)] <- runX (readDocument [] "xmlpath.xml" >>> process) print item print names</lang>
HicEst
<lang hicest>CHARACTER xml*1000, output*1000
READ(ClipBoard) xml
EDIT(Text=xml, Right='<item', Right=5, GetPosition=a, Right='</item>', Left, GetPosition=z) WRITE(Text=output) xml( a : z), $CRLF
i = 1
1 EDIT(Text=xml, SetPosition=i, SePaRators='<>', Right='<price>', Word=1, Parse=price, GetPosition=i, ERror=99)
IF(i > 0) THEN
WRITE(Text=output, APPend) 'Price element = ', price, $CRLF
GOTO 1 ! HicEst does not have a "WHILE"
ENDIF
EDIT(Text=xml, SPR='<>', R='<name>', W=1, WordEnd=$CR, APpendTo=output, DO=999) WRITE(ClipBoard) TRIM(output) </lang>
<lang hicest> upc="123456789" stock="12">
<name>Invisibility Cream</name>
<price>14.50</price>
<description>Makes you invisible</description>
Price element = 14.50 Price element = 23.99 Price element = 4.95 Price element = 3.56 Invisibility Cream
Levitation Salve Blork and Freen Instameal Grob winglets
</lang>
Java
<lang java>import java.io.StringReader; import javax.xml.parsers.DocumentBuilderFactory; import javax.xml.xpath.XPath; import javax.xml.xpath.XPathConstants; import javax.xml.xpath.XPathFactory; import org.w3c.dom.Document; import org.w3c.dom.Node; import org.w3c.dom.NodeList; import org.xml.sax.InputSource;
public class XMLParser { final static String xmlStr = "<inventory title=\"OmniCorp Store #45x10^3\">" + "
" + "
" + "</inventory>";
public static void main(String[] args) { try { Document doc = DocumentBuilderFactory.newInstance() .newDocumentBuilder() .parse(new InputSource(new StringReader(xmlStr))); XPath xpath = XPathFactory.newInstance().newXPath(); // 1 System.out.println(((Node) xpath.evaluate( "/inventory/section/item[1]", doc, XPathConstants.NODE)) .getAttributes().getNamedItem("upc")); // 2, 3 NodeList nodes = (NodeList) xpath.evaluate( "/inventory/section/item/price", doc, XPathConstants.NODESET); for (int i = 0; i < nodes.getLength(); i++) System.out.println(nodes.item(i).getTextContent()); } catch (Exception e) { System.out.println("Error ocurred while parsing XML."); } } }</lang>
JavaScript
<lang javascript>//create XMLDocument object from file var xhr = new XMLHttpRequest(); xhr.open('GET', 'file.xml', false); xhr.send(null); var doc = xhr.responseXML;
//get first <item> element var firstItem = doc.evaluate( '//item[1]', doc, null, XPathResult.FIRST_ORDERED_NODE_TYPE, null ).singleNodeValue; alert( firstItem.textContent );
//output contents of <price> elements var prices = doc.evaluate( '//price', doc, null, XPathResult.ANY_TYPE, null ); for( var price = prices.iterateNext(); price != null; price = prices.iterateNext() ) {
alert( price.textContent );
}
//add <name> elements to array var names = doc.evaluate( '//name', doc, null, XPathResult.ANY_TYPE, null); var namesArray = []; for( var name = names.iterateNext(); name != null; name = names.iterateNext() ) {
namesArray.push( name );
} alert( namesArray );</lang>
Although some browsers support XPath, working with XML is much easier with E4X.
<lang javascript>//create XML object from file var xhr = new XMLHttpRequest(); xhr.open('GET', 'file.xml', false); xhr.send(null); var doc = new XML(xhr.responseText);
//get first <item> element var firstItem = doc..item[0]; alert( firstItem );
//output contents of <price> elements for each( var price in doc..price ) {
alert( price );
}
//add <name> elements to array var names = []; for each( var name in doc..name ) {
names.push( name );
} alert( names );</lang>
Lasso
Lasso has built in support for both XML handling and Xpaths <lang Lasso>// makes extracting attribute values easier define xml_attrmap(in::xml_namedNodeMap_attr) => { local(out = map) with attr in #in do #out->insert(#attr->name = #attr->value) return #out }
local( text = '<inventory title="OmniCorp Store #45x10^3">
<item upc="123456789" stock="12"> <name>Invisibility Cream</name> <price>14.50</price> <description>Makes you invisible</description> </item> <item upc="445322344" stock="18"> <name>Levitation Salve</name> <price>23.99</price> <description>Levitate yourself for up to 3 hours per application</description> </item> <item upc="485672034" stock="653"> <name>Blork and Freen Instameal</name> <price>4.95</price> <description>A tasty meal in a tablet; just add water</description> </item> <item upc="132957764" stock="44"> <name>Grob winglets</name> <price>3.56</price> <description>Tender winglets of Grob. Just add water</description> </item>
</inventory> ', xml = xml(#text) )
local( items = #xml -> extract('//item'), firstitem = #items -> first, itemattr = xml_attrmap(#firstitem -> attributes), newprices = array )
'First item:
UPC: '
- itemattr -> find('upc')
' (stock: '
- itemattr -> find('stock')
')
'
- firstitem -> extractone('name') -> nodevalue
' ['
- firstitem -> extractone('price') -> nodevalue
'] ('
- firstitem -> extractone('description') -> nodevalue
')
'
with item in #items
let name = #item -> extractone('name') -> nodevalue
let price = #item -> extractone('price') -> nodevalue
do {
#newprices -> insert(#name + ': ' + (decimal(#price) * 1.10) -> asstring(-precision = 2) + ' (' + #price + ')')
}
'Adjusted prices:
'
- newprices -> join('
')
'
'
'Array with all names:
'
- xml -> extract('//name') -> asstaticarray</lang>
Output:
First item: UPC: 123456789 (stock: 12) Invisibility Cream [14.50] (Makes you invisible) Adjusted prices: Invisibility Cream: 15.95 (14.50) Levitation Salve: 26.39 (23.99) Blork and Freen Instameal: 5.45 (4.95) Grob winglets: 3.92 (3.56) Array with all names: staticarray(Invisibility Cream, Levitation Salve, Blork and Freen Instameal, Grob winglets)
LiveCode
Copy the xml in this task into a text field called "FieldXML" <lang LiveCode>put revXMLCreateTree(fld "FieldXML",true,true,false) into xmltree
// task 1 put revXMLEvaluateXPath(xmltree,"//item[1]") into nodepath put revXMLText(xmltree,nodepath,true)
// task 2 put revXMLDataFromXPathQuery(xmltree,"//item/price",,comma)
// task 3 put revXMLDataFromXPathQuery(xmltree,"//name") into namenodes filter namenodes without empty split namenodes using cr put namenodes is an array</lang>
Lua
Requires LuaExpat <lang lua>require 'lxp' data = [[<inventory title="OmniCorp Store #45x10^3">
<item upc="123456789" stock="12"> <name>Invisibility Cream</name> <price>14.50</price> <description>Makes you invisible</description> </item> <item upc="445322344" stock="18"> <name>Levitation Salve</name> <price>23.99</price> <description>Levitate yourself for up to 3 hours per application</description> </item> <item upc="485672034" stock="653"> <name>Blork and Freen Instameal</name> <price>4.95</price> <description>A tasty meal in a tablet; just add water</description> </item> <item upc="132957764" stock="44"> <name>Grob winglets</name> <price>3.56</price> <description>Tender winglets of Grob. Just add water</description> </item>
</inventory>]] local first = true local names, prices = {}, {} p = lxp.new({StartElement = function (parser, name) local a, b, c = parser:pos() --line, offset, pos if name == 'item' and first then print(data:match('.-</item>', c - b + 1)) first = false end if name == 'name' then names[#names+1] = data:match('>(.-)<', c) end if name == 'price' then prices[#prices+1] = data:match('>(.-)<', c) end end})
p:parse(data) p:close()
print('Name: ', table.concat(names, ', ')) print('Price: ', table.concat(prices, ', '))</lang>
Output:
<item upc="123456789" stock="12">
<name>Invisibility Cream</name>
<price>14.50</price>
<description>Makes you invisible</description>
</item>
Name: Invisibility Cream, Levitation Salve, Blork and Freen Instameal, Grob winglets
Price: 14.50, 23.99, 4.95, 3.56
Mathematica
<lang Mathematica>example = Import["test.txt", "XML"]; Cases[example, XMLElement["item", _ , _] , Infinity] // First Cases[example, XMLElement["price", _, List[n_]] -> n, Infinity] // Column Cases[example, XMLElement["name", _, List[n_]] -> n, Infinity] // Column</lang>
Output:
XMLElement[item,{upc->123456789,stock->12},
{XMLElement[name,{},{Invisibility Cream}],XMLElement[price,{},{14.50}],XMLElement[description,{},{Makes you invisible}]}]
14.50
23.99
4.95
3.56
Invisibility Cream
Levitation Salve
Blork and Freen Instameal
Grob winglets
NetRexx
<lang NetRexx>/* NetRexx */ options replace format comments java crossref symbols binary
import javax.xml.parsers. import javax.xml.xpath. import org.w3c.dom. import org.xml.sax.
xmlStr = -
|| '<inventory title="OmniCorp Store #45x10^3">' - || '' - || ' <item upc="123456789" stock="12">' - || ' <name>Invisibility Cream</name>' - || ' <price>14.50</price>' - || ' <description>Makes you invisible</description>' - || ' </item>' - || ' <item upc="445322344" stock="18">' - || ' <name>Levitation Salve</name>' - || ' <price>23.99</price>' - || ' <description>Levitate yourself for up to 3 hours per application</description>' - || ' </item>' - || ' ' - || '' - || ' <item upc="485672034" stock="653">' - || ' <name>Blork and Freen Instameal</name>' - || ' <price>4.95</price>' - || ' <description>A tasty meal in a tablet; just add water</description>' - || ' </item>' - || ' <item upc="132957764" stock="44">' - || ' <name>Grob winglets</name>' - || ' <price>3.56</price>' - || ' <description>Tender winglets of Grob. Just add priwater</description>' - || ' </item>' - || ' ' - || '</inventory>'
expr1 = '/inventory/section/item[1]' expr2 = '/inventory/section/item/price' expr3 = '/inventory/section/item/name' attr1 = 'upc'
do
doc = DocumentBuilderFactory.newInstance().newDocumentBuilder().parse(InputSource(StringReader(xmlStr))) xpath = XPathFactory.newInstance().newXPath()
-- Extract attribute from 1st item element say expr1 say " "(Node xpath.evaluate(expr1, doc, XPathConstants.NODE)).getAttributes().getNamedItem(attr1) say
-- Extract and display all price elments nodes = NodeList xpath.evaluate(expr2, doc, XPathConstants.NODESET) say expr2 loop i_ = 0 to nodes.getLength() - 1 say Rexx(nodes.item(i_).getTextContent()).format(10, 2) end i_ say
-- Extract elements and store in an ArrayList nameList = java.util.List nameList = ArrayList() nodes = NodeList xpath.evaluate(expr3, doc, XPathConstants.NODESET) loop i_ = 0 to nodes.getLength() - 1 nameList.add(nodes.item(i_).getTextContent()) end i_
-- display contents of ArrayList say expr3 loop n_ = 0 to nameList.size() - 1 say " "nameList.get(n_) end n_ say
catch ex = Exception
ex.printStackTrace()
end
return </lang> Output:
/inventory/section/item[1]
upc="123456789"
/inventory/section/item/price
14.50
23.99
4.95
3.56
/inventory/section/item/name
Invisibility Cream
Levitation Salve
Blork and Freen Instameal
Grob winglets
Nim
<lang nim>import xmldom, xmldomparser
let doc = "test3.xml".loadXMLFile.documentElement
- 1st task: retrieve the first "item" element
let i = doc.getElementsByTagName("item")[0]
- 2nd task: perform an action on each "price" element (print it out)
for j in doc.getElementsByTagName "price":
echo j.firstChild.PText.data
- 3rd task: get an array of all the "name" elements
let namesArray = doc.getElementsByTagName "name"</lang>
Objeck
XPath is used to fetch element tags. <lang objeck> use XML;
bundle Default {
class Test {
function : Main(args : String[]) ~ Nil {
in := String->New();
in->Append("<inventory title=\"OmniCorp Store #45x10^3\">");
in->Append("");
in->Append("<item upc=\"123456789\" stock=\"12\">");
in->Append("<name>Invisibility Cream</name>");
in->Append("<price>14.50</price>");
in->Append("<description>Makes you invisible</description>");
in->Append("</item>");
in->Append("<item upc=\"445322344\" stock=\"18\">");
in->Append("<name>Levitation Salve</name>");
in->Append("<price>23.99</price>");
in->Append("<description>Levitate yourself for up to 3 hours per application</description>");
in->Append("</item>");
in->Append(" ");
in->Append("");
in->Append("<item upc=\"485672034\" stock=\"653\">");
in->Append("<name>Blork and Freen Instameal</name>");
in->Append("<price>4.95</price>");
in->Append("<description>A tasty meal in a tablet; just add water</description>");
in->Append("</item>");
in->Append("<item upc=\"132957764\" stock=\"44\">");
in->Append("<name>Grob winglets</name>");
in->Append("<price>3.56</price>");
in->Append("<description>Tender winglets of Grob. Just add water</description>");
in->Append("</item>");
in->Append(" ");
in->Append("</inventory>");
parser := XmlParser->New(in);
if(parser->Parse()) {
# get first item
results := parser->FindElements("//inventory/section[1]/item[1]");
if(results <> Nil) {
IO.Console->Instance()->Print("items: ")->PrintLine(results->Size());
};
# get all prices
results := parser->FindElements("//inventory/section/item/price");
if(results <> Nil) {
each(i : results) {
element := results->Get(i)->As(XMLElement);
element->GetContent()->PrintLine();
};
};
# get names
results := parser->FindElements("//inventory/section/item/name");
if(results <> Nil) {
IO.Console->Instance()->Print("names: ")->PrintLine(results->Size());
};
};
}
}
} </lang>
Oz
We implement a small subset of XPath for this task: <lang oz>declare
[XMLParser] = {Module.link ['x-oz://system/xml/Parser.ozf']}
proc {Main Data}
Parser = {New XMLParser.parser init}
[Doc] = {Parser parseVS(Data $)}
FirstItem = {XPath Doc [inventory section item]}.1
Prices = {XPath Doc [inventory section item price Text]}
Names = {XPath Doc [inventory section item name]}
in
{ForAll Prices System.showInfo}
end
%% %% Emulation of some XPath functionality: %%
fun {XPath Doc Path}
P|Pr = Path
in
Doc.name = P %% assert
{FoldL Pr XPathStep [Doc]}
end
fun {XPathStep Elements P}
if {IsProcedure P} then
{Map Elements P}
else
{FilteredChildren Elements P}
end
end
%% A flat list of all Type-children of all Elements.
fun {FilteredChildren Elements Type}
{Flatten
{Map Elements
fun {$ E}
{Filter E.children fun {$ X} case X of element(name:!Type ...) then true else false end end}
end}} end
%% PCDATA of an element as a ByteString
fun {Text Element}
Texts = for Child in Element.children collect:C do
case Child of text(data:BS ...) then {C BS} end end
in
{FoldR Texts ByteString.append {ByteString.make nil}}
end
Data =
"<inventory title=\"OmniCorp Store #45x10^3\">"
#" "
#" <item upc=\"123456789\" stock=\"12\">"
#" <name>Invisibility Cream</name>"
#" <price>14.50</price>"
#" <description>Makes you invisible</description>"
#" </item>"
#" <item upc=\"445322344\" stock=\"18\">"
#" <name>Levitation Salve</name>"
#" <price>23.99</price>"
#" <description>Levitate yourself for up to 3 hours per application</description>"
#" </item>"
#" "
#" "
#" <item upc=\"485672034\" stock=\"653\">"
#" <name>Blork and Freen Instameal</name>"
#" <price>4.95</price>"
#" <description>A tasty meal in a tablet; just add water</description>"
#" </item>"
#" <item upc=\"132957764\" stock=\"44\">"
#" <name>Grob winglets</name>"
#" <price>3.56</price>"
#" <description>Tender winglets of Grob. Just add water</description>"
#" </item>"
#" "
#"</inventory>"
in
{Main Data}</lang>
Perl
<lang perl>use XML::XPath qw();
my $x = XML::XPath->new('<inventory ... </inventory>');
[$x->findnodes('//item[1]')->get_nodelist]->[0]; print $x->findnodes_as_string('//price'); $x->findnodes('//name')->get_nodelist;</lang>
PHP
<lang php><?php //PHP5 only example due to changes in XML extensions between version 4 and 5 (Tested on PHP5.2.0) $doc = DOMDocument::loadXML('<inventory title="OmniCorp Store #45x10^3">...</inventory>'); //Load from file instead with $doc = DOMDocument::load('filename'); $xpath = new DOMXPath($doc); /*
1st Task: Retrieve the first "item" element
- /
$nodelist = $xpath->query('//item'); $result = $nodelist->item(0); /*
2nd task: Perform an action on each "price" element (print it out)
- /
$nodelist = $xpath->query('//price'); for($i = 0; $i < $nodelist->length; $i++) {
//print each price element in the DOMNodeList instance, $nodelist, as text/xml followed by a newline print $doc->saveXML($nodelist->item($i))."\n";
} /*
3rd Task: Get an array of all the "name" elements
- /
$nodelist = $xpath->query('//name'); //our array to hold all the name elements, though in practice you'd probably not need to do this and simply use the DOMNodeList $result = array(); //a different way of iterating through the DOMNodeList foreach($nodelist as $node) {
$result[] = $node;
}</lang>
PicoLisp
<lang PicoLisp>(load "@lib/xm.l")
(let Sections (body (in "file.xml" (xml)))
(pretty (car (body (car Sections))))
(prinl)
(for S Sections
(for L (body S)
(prinl (car (body L 'price))) ) )
(make
(for S Sections
(for L (body S)
(link (car (body L 'name))) ) ) ) )</lang>
Output:
(item
((upc . "123456789") (stock . "12"))
(name NIL "Invisibility Cream")
(price NIL "14.50")
(description NIL "Makes you invisible") )
14.50
23.99
4.95
3.56
-> ("Invisibility Cream" "Levitation Salve" "Blork and Freen Instameal" "Grob winglets")
Python
<lang python># Python has basic xml parsing built in
from xml.dom import minidom
xmlfile = file("test3.xml") # load xml document from file xmldoc = minidom.parse(xmlfile).documentElement # parse from file stream or... xmldoc = minidom.parseString("<inventory title="OmniCorp Store #45x10^3">...</inventory>").documentElement # alternatively, parse a string
- 1st Task: Retrieve the first "item" element
i = xmldoc.getElementsByTagName("item") # get a list of all "item" tags firstItemElement = i[0] # get the first element
- 2nd task: Perform an action on each "price" element (print it out)
for j in xmldoc.getElementsByTagName("price"): # get a list of all "price" tags print j.childNodes[0].data # XML Element . TextNode . data of textnode
- 3rd Task: Get an array of all the "name" elements
namesArray = xmldoc.getElementsByTagName("name")</lang> In Python 2.5+ you can use ElementTree's limited XPath support <lang python> import xml.etree.ElementTree as ET
xml = open('inventory.xml').read() doc = ET.fromstring(xml)
doc = ET.parse('inventory.xml') # or load it directly
- Note, ElementTree's root is the top level element. So you need ".//" to really start searching from top
- Return first Item
item1 = doc.find("section/item") # or ".//item"
- Print each price
for p in doc.findall("section/item/price"): # or ".//price"
print "{0:0.2f}".format(float(p.text)) # could raise exception on missing text or invalid float() conversion
- list of names
names = doc.findall("section/item/name") # or ".//name"</lang> Or, you can install the lxml package and get full XPath support <lang python> from lxml import etree
xml = open('inventory.xml').read() doc = etree.fromstring(xml)
doc = etree.parse('inventory.xml') # or load it directly
- Return first item
item1 = doc.xpath("//section[1]/item[1]")
- Print each price
for p in doc.xpath("//price"):
print "{0:0.2f}".format(float(p.text)) # could raise exception on missing text or invalid float() conversion
names = doc.xpath("//name") # list of names</lang>
R
<lang R>## Require the XML package you can download from http://www.omegahat.org/RSXML/ library("XML") doc <- xmlInternalTreeParse("test3.xml")
- 1st Task: Retrieve the first "item" element
(firstItemElement <- getNodeSet(doc, "//item")1)
- 2nd task: Perform an action on each "price" element (print it out)
prices <- sapply(getNodeSet(doc, "//price"), xmlValue) for(i in 1:length(prices)) print(prices[i])
- 3rd Task: Get an array of all the "name" elements
(namesArray <- sapply(getNodeSet(doc, "//name"), xmlValue))</lang>
Racket
<lang racket>
- lang at-exp racket
(define input @~a{
<inventory title="OmniCorp Store #45x10^3"><item upc="123456789" stock="12"> <name>Invisibility Cream</name> <price>14.50</price> <description>Makes you invisible</description> </item> <item upc="445322344" stock="18"> <name>Levitation Salve</name> <price>23.99</price> <description>Levitate yourself for up to 3 hours per application</description> </item> <item upc="485672034" stock="653"> <name>Blork and Freen Instameal</name> <price>4.95</price> <description>A tasty meal in a tablet; just add water</description> </item> <item upc="132957764" stock="44"> <name>Grob winglets</name> <price>3.56</price> <description>Tender winglets of Grob. Just add water</description> </item> </inventory>})
(require xml xml/path)
(define data (xml->xexpr
((eliminate-whitespace '(inventory section item))
(read-xml/element (open-input-string input)))))
- Retrieve the first "item" element
(displayln (xexpr->string (se-path* '(item) data)))
- => <name>Invisibility Cream</name>
- Perform an action on each "price" element (print it out)
(printf "Prices: ~a\n" (string-join (se-path*/list '(item price) data) ", "))
- => Prices
- 14.50, 23.99, 4.95, 3.56
- Get an array of all the "name" elements
(se-path*/list '(item name) data)
- => '("Invisibility Cream" "Levitation Salve" "Blork and Freen Instameal" "Grob winglets")
</lang>
Rascal
<lang rascal>import lang::xml::DOM; import Prelude;
public void get_first_item(loc a){ D = parseXMLDOM(readFile(a)); top-down-break visit(D){ case E:element(_,"item",_): return println(xmlPretty(E)); }; }
public void print_prices(loc a){ D = parseXMLDOM(readFile(a)); for(/element(_,"price",[charData(/str p)]) := D) println(p); }
public list[str] get_names(loc a){ D = parseXMLDOM(readFile(a)); L = []; for(/element(_,"name",[charData(/str n)]) := D) L += n; return L; }</lang> Example output: <lang rascal>rascal>get_first_item(|file:///Users/.../Desktop/xmlpath.xml|) <?xml version="1.0" encoding="UTF-8"?> <item stock="12" upc="123456789">
<name>Invisibility Cream</name> <price>14.50</price> <description>Makes you invisible</description>
</item>
ok
rascal>print_prices(|file:///Users/.../Desktop/xmlpath.xml|) 14.50 23.99 4.95 3.56 ok
rascal>get_names(|file:///Users/.../Desktop/xmlpath.xml|) list[str]: ["Invisibility Cream","Levitation Salve","Blork and Freen Instameal","Grob winglets"]</lang>
REXX
hard coded parsing
<lang rexx>/*REXX program to parse various queries on an XML document (from a file). */ iFID='XPATH.XML' /*name of the input XML file (doc). */ $= /*string will contain the file's text. */
do j=1 while lines(iFID)\==0 /*read the entire file into a string. */
$=$ linein(iFID) /*append the line to the $ string. */
end /*j*/
/* [↓] show 1st ITEM in the document*/
parse var $ '<item ' item "</item>" say center('first item:',length(space(item)),'─') /*display a nice header.*/ say space(item)
/* [↓] show all PRICES in the document*/
prices= /*nullify the list and add/append to it*/ $$=$ /*start with a fresh copy of document. */
do until $$= /* [↓] keep parsing string until done.*/
parse var $$ '<price>' price '</price>' $$
prices=prices price /*add/append the price to the list. */
end /*until*/
say say center('prices:',length(space(prices)),'─') /*display a nice header.*/ say space(prices)
/* [↓] show all NAMES in the document*/
names.= /*nullify the list and add/append to it*/ L=length(' names: ') /*maximum length of any one list name. */ $$=$ /*start with a fresh copy of document. */
do #=1 until $$= /* [↓] keep parsing string until done.*/
parse var $$ '<name>' names.# '</name>' $$
L=max(L,length(names.#)) /*L: is used to find the widest name. */
end /*#*/
names.0=#-1; say /*adjust the number of names (DO loop).*/ say center('names:',L,'─') /*display a nicely formatted header. */
do k=1 for names.0 /*display all the names in the list. */
say names.k /*display a name from the NAMES list.*/
end /*k*/
/*stick a fork in it, we're all done. */</lang>
output
──────────────────────────────────────────────────────────first item:────────────────────────────────────────────────────────── upc="123456789" stock="12"> <name>Invisibility Cream</name> <price>14.50</price> <description>Makes you invisible</description> ───────prices:─────── 14.50 23.99 4.95 3.56 ─────────names:────────── Invisibility Cream Levitation Salve Blork and Freen Instameal Grob winglets
generic parsing
<lang rexx>/*REXX program to parse various queries on an XML document (from a file). */ iFID='XPATH.XML' /*name of the input XML file (doc). */ $= /*string will contain the file's text. */
do j=1 while lines(iFID)\==0 /*read the entire file into a string. */
$=$ linein(iFID) /*append the line to the $ string. */
end /*j*/
/* [↓] display 1st ITEM in document. */
call parser 'item', 0 /*go and parse the all the ITEMs. */ say center('first item:',@L.1,'─') /*display a nicely formatted header. */ say @.1; say /*display the first ITEM found. */
call parser 'price' /*go and parse all the PRICEs. */ say center('prices:',length(@@@),'─') /*display a nicely formatted header. */ say @@@; say /*display a list of all the prices. */
call parser 'name' say center('names:',@L,'─') /*display a nicely formatted header. */
do k=1 for # /*display all the names in the list. */
say @.k /*display a name from the NAMES list.*/
end /*k*/
exit /*stick a fork in it, we're all done. */ /*────────────────────────────────────────────────────────────────────────────*/ parser: parse arg yy,tail,,@. @@. @@@; $$=$; @L=9; yb='<'yy; ye='</'yy">" tail=word(tail 1, 1) /*use a tail ">" or not?*/
do #=1 until $$= /*parse complete XML doc. */
if tail then parse var $$ (yb) '>' @@.# (ye) $$ /*find meat.*/
else parse var $$ (yb) @@.# (ye) $$ /* " " */
@.#=space(@@.#); @@@=space(@@@ @.#) /*shrink; @@@=list of YY.*/
@L.#=length(@.#); @L=max(@L,@L.#) /*length; maximum length. */
end /*#*/
- =#-1 /*adjust # of thing found.*/
return</lang> output is the same as the 1st version.
Ruby
<lang ruby>#Example taken from the REXML tutorial (http://www.germane-software.com/software/rexml/docs/tutorial.html) require "rexml/document" include REXML
- create the REXML Document from the string (%q is Ruby's multiline string, everything between the two @-characters is the string)
doc = Document.new(
%q@<inventory title="OmniCorp Store #45x10^3">
...
</inventory>
@
)
- The invisibility cream is the first <item>
invisibility = XPath.first( doc, "//item" )
- Prints out all of the prices
XPath.each( doc, "//price") { |element| puts element.text }
- Gets an array of all of the "name" elements in the document.
names = XPath.match( doc, "//name" )</lang>
Scala
The problem description isn't clear on whether what is wanted is the element or the text. Because of that, I'm doing both except for the first problem.
The commands are being inputted into Scala's REPL, to better show the results.
<lang scala>scala> val xml = <inventory title="OmniCorp Store #45x10^3">
|| <item upc="123456789" stock="12"> | <name>Invisibility Cream</name> | <price>14.50</price> | <description>Makes you invisible</description> | </item> | <item upc="445322344" stock="18"> | <name>Levitation Salve</name> | <price>23.99</price> | <description>Levitate yourself for up to 3 hours per application</description> | </item> | || <item upc="485672034" stock="653"> | <name>Blork and Freen Instameal</name> | <price>4.95</price> | <description>A tasty meal in a tablet; just add water</description> | </item> | <item upc="132957764" stock="44"> | <name>Grob winglets</name> | <price>3.56</price> | <description>Tender winglets of Grob. Just add water</description> | </item> | | </inventory>
xml: scala.xml.Elem = <inventory title="OmniCorp Store #45x10^3">
<item upc="123456789" stock="12"> <name>Invisibility Cream</name> <price>14.50</price> <description>Makes you invisible</description> </item> <item upc="445322344" stock="18"> <name>Levitation Salve</name> <price>23.99</price> <description>Levitate yourself for up to 3 hours per application</description> </item> <item upc="485672034" stock="653"> <name>Blork and Freen Instameal</name> <price>4.95</price> <description>A tasty meal in a tablet; just add water</description> </item> <item upc="132957764" stock="44"> <name>Grob winglets</name> <price>3.56</price> <description>Tender winglets of Grob. Just add water</description> </item> </inventory>
scala> val firstItem = xml \\ "item" head firstItem: scala.xml.Node = <item upc="123456789" stock="12">
<name>Invisibility Cream</name>
<price>14.50</price>
<description>Makes you invisible</description>
</item>
scala> xml \\ "price" foreach println <price>14.50</price> <price>23.99</price> <price>4.95</price> <price>3.56</price>
scala> xml \\ "price" map (_ text) foreach println 14.50 23.99 4.95 3.56
scala> val elements = xml \\ "name" toArray elements: Array[scala.xml.Node] = Array(<name>Invisibility Cream</name>, <name>Levitation Salve</name>, <name>Blork and Freen Instameal</name>, <name>Grob winglets</name>)
scala> val values = xml \\ "name" map (_ text) toArray values: Array[String] = Array(Invisibility Cream, Levitation Salve, Blork and Freen Instameal, Grob winglets)</lang>
Sidef
<lang ruby>require('XML::XPath');
var x = %s'XML::XPath'.new(ARGF.slurp);
[x.findnodes('//item[1]')][0]; say [x.findnodes('//price')].map{x.getNodeText(_)}; [x.findnodes('//name')];</lang>
- Output:
[14.5, 23.99, 4.95, 3.56]
Tcl
<lang tcl># assume $xml holds the XML data package require tdom set doc [dom parse $xml] set root [$doc documentElement]
set allNames [$root selectNodes //name] puts [llength $allNames] ;# ==> 4
set firstItem [lindex [$root selectNodes //item] 0] puts [$firstItem @upc] ;# ==> 123456789
foreach node [$root selectNodes //price] {
puts [$node text]
}</lang>
TUSCRIPT
<lang tuscript> $$ MODE TUSCRIPT,{} MODE DATA $$ XML=* <inventory title="OmniCorp Store #45x10³">
<item upc="123456789" stock="12"> <name>Invisibility Cream</name> <price>14.50</price> <description>Makes you invisible</description> </item> <item upc="445322344" stock="18"> <name>Levitation Salve</name> <price>23.99</price> <description>Levitate yourself for up to 3 hours per application</description> </item> <item upc="485672034" stock="653"> <name>Blork and Freen Instameal</name> <price>4.95</price> <description>A tasty meal in a tablet; just add water</description> </item> <item upc="132957764" stock="44"> <name>Grob winglets</name> <price>3.56</price> <description>Tender winglets of Grob. Just add water</description> </item>
</inventory> $$ MODE TUSCRIPT
FILE = "test.xml" ERROR/STOP CREATE (file,fdf-o,-std-) FILE/ERASE/UTF8 $FILE = xml
BUILD S_TABLE beg=":<item*>:<name>:<price>:" BUILD S_TABLE end=":</item>:</name>:</price>:" BUILD S_TABLE modifiedbeg=":<name>:<price>:" BUILD S_TABLE modifiedend=":</name>:</price>:" firstitem=names="",countitem=0 ACCESS q: READ/STREAM/UTF8 $FILE s,a/beg+t+e/end LOOP READ/EXIT q IF (a=="<name>") names=APPEND(names,t) IF (a=="<price>") PRINT t IF (a.sw."<item") countitem=1 IF (countitem==1) THEN firstitem=CONCAT(firstitem,a) firstitem=CONCAT(firstitem,t) firstitem=CONCAT(firstitem,e)
IF (e=="</item>") THEN COUNTITEM=0 MODIFY ACCESS q s_TABLE modifiedbeg,-,modifiedend ENDIF
ENDIF ENDLOOP ENDACCESS q ERROR/STOP CLOSE (file) firstitem=EXCHANGE (firstitem,":{2-00} ::") firstitem=INDENT_TAGS (firstitem,-," ") names=SPLIT(names) TRACE *firstitem,names </lang> Output:
14.50
23.99
4.95
3.56
TRACE * 63 -*TUSTEP.EDT
firstitem = *
1 = <item upc="123456789" stock="12">
2 = <name>Invisibility Cream</name>
3 = <price>14.50</price>
4 = <description>Makes you invisible</description>
5 = </item>
names = *
1 = Invisibility Cream
2 = Levitation Salve
3 = Blork and Freen Instameal
4 = Grob winglets
VBScript
<lang vb> Set objXMLDoc = CreateObject("msxml2.domdocument")
objXMLDoc.load("In.xml")
Set item_nodes = objXMLDoc.selectNodes("//item") i = 1 For Each item In item_nodes If i = 1 Then WScript.StdOut.Write item.xml WScript.StdOut.WriteBlankLines(2) Exit For End If Next
Set price_nodes = objXMLDoc.selectNodes("//price") list_price = "" For Each price In price_nodes list_price = list_price & price.text & ", " Next WScript.StdOut.Write list_price WScript.StdOut.WriteBlankLines(2)
Set name_nodes = objXMLDoc.selectNodes("//name") list_name = "" For Each name In name_nodes list_name = list_name & name.text & ", " Next WScript.StdOut.Write list_name WScript.StdOut.WriteBlankLines(2) </lang>
- Output:
<item upc="123456789" stock="12"> <name>Invisibility Cream</name> <price>14.50</price> <description>Makes you invisible</description> </item> 14.50, 23.99, 4.95, 3.56, Invisibility Cream, Levitation Salve, Blork and Freen Instameal, Grob winglets,
Visual Basic .NET
<lang vbnet>Dim first_item = xml.XPathSelectElement("//item") Console.WriteLine(first_item)
For Each price In xml.XPathSelectElements("//price")
Console.WriteLine(price.Value)
Next
Dim names = (From item In xml.XPathSelectElements("//name") Select item.Value).ToArray</lang>
XProc
<lang xml><p:pipeline xmlns:p="http://www.w3.org/ns/xproc"
name="one-two-three"
version="1.0">
<p:identity>
<p:input port="source">
<p:inline>
<root>
<first/>
<prices/>
<names/>
</root>
</p:inline>
</p:input>
</p:identity>
<p:insert match="/root/first" position="first-child">
<p:input port="insertion" select="(//item)[1]">
<p:pipe port="source" step="one-two-three"/>
</p:input>
</p:insert>
<p:insert match="/root/prices" position="first-child">
<p:input port="insertion" select="//price">
<p:pipe port="source" step="one-two-three"/>
</p:input>
</p:insert>
<p:insert match="/root/names" position="first-child">
<p:input port="insertion" select="//name">
<p:pipe port="source" step="one-two-three"/>
</p:input>
</p:insert>
</p:pipeline></lang>
XQuery
<lang xquery>(:
1. Retrieve the first "item" element Notice the braces around //item. This evaluates first all item elements and then retrieving the first one. Whithout the braces you get the first item for every section.
- )
let $firstItem := (//item)[1]
(: 2. Perform an action on each "price" element (print it out) :) let $price := //price/data(.)
(: 3. Get an array of all the "name" elements :) let $names := //name
return
<result>
<firstItem>{$firstItem}</firstItem>
<prices>{$price}</prices>
<names>{$names}</names>
</result></lang>
Performing this XQuery on the given input document results in <lang xquery><?xml version="1.0" encoding="UTF-8"?> <result>
<firstItem>
<item upc="123456789" stock="12">
<name>Invisibility Cream</name>
<price>14.50</price>
<description>Makes you invisible</description>
</item>
</firstItem>
<prices>14.50 23.99 4.95 3.56</prices>
<names>
<name>Invisibility Cream</name>
<name>Levitation Salve</name>
<name>Blork and Freen Instameal</name>
<name>Grob winglets</name>
</names>
</result></lang>
XSLT
<lang xml><xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:output method="text" /> <xsl:template match="/"> <xsl:text>
The first item element is</xsl:text>
<xsl:value-of select="//item[1]" /> <xsl:text>
The prices are: </xsl:text>
<xsl:for-each select="//price">
<xsl:text>
</xsl:text>
<xsl:copy-of select="." />
</xsl:for-each>
<xsl:text>
The names are: </xsl:text>
<xsl:copy-of select="//name" /> </xsl:template>
</xsl:stylesheet></lang>
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